Air passage device

ABSTRACT

An air passage device for installation into a mounting opening ( 50 ) in a wall ( 51 ) for components generating waste heat, such as a switch box, includes a base housing ( 21; 221 ) with a fan support ( 25 ) and a design cover ( 80; 280 ), wherein the design cover ( 80; 280 ) has on an air inlet side a covering device ( 100 ) constructed as a fan grid ( 10; 210 ) with sheet elements ( 90, 90′; 290, 290 ′). At least one swivellable sheet element ( 90 ) or at least one flexible, tongue-shaped side wall section ( 235 ), separated from the remaining side wall surface by slits ( 332, 333 ) running transversely to the longitudinal direction of the side wall, is formed in the region of the upper side wall of the design cover ( 80; 280 ) facing away from the swivel axis ( 26; 226 ) for swivelling the design cover ( 80; 280 ), wherein the sheet element ( 90 ) and the tongue-shaped side wall section ( 235 ) are formed between the design cover ( 80; 280 ) and the base housing ( 21; 221 ) as a detachable and lockable detent connection ( 40; 240 ), that can be operated by a finger.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air passage device, particularly afilter fan or outlet filter.

2. Description of the Related Art

In the case of components arranged in a housing, which generatecorresponding waste heat, it is necessary to carry off the waste heatfrom the housing and control a temperature in the housing by blowing inor drawing off ambient air into the interior of the housing to a greateror lesser extent by means of the fan. Computer housings are a knownexample of this. Usually, such housings are provided with a filter fanwhich either runs continuously or is switched on and off by a controlarrangement, depending on a temperature in the housing. The filter fanis arranged in a recess of a wall of the housing and is fixed forexample by means of screw connections. At the same time, correspondingair outlet slits are provided for the outlet of air at another locationin the housing. However, the installation of such filter fans isfrequently laborious, because when screw connections are used, there isscarcely any play available in order to be able to also subsequentlyvisually align the filter fan.

The filter mats which are used in these filter fans are arranged betweenthe outer fan grid and the base housing. The fan grid is detachablyconnected to the base housing by means of clamping- or detentconnections or screw connections. If a used filter mat is to beexchanged for a new filter mat, the entire fan grid must be removed fromthe base housing, with the connection means in most cases having to beloosened by means of tools.

A filter fan housing with an air inlet on the base side and an airoutlet which is at right-angles to the air inlet, with the air outletopening being connected with the interior of a switch box, is known fromDE 100 51 643 A1. In the interior of the housing, a filter mat isarranged which assumes an oblique position, so that the air current isguided from the air inlet to the air outlet through the filter mat. Theinterior of the filter mat housing is accessible via a closablemaintenance opening, in order to be able to exchange a filter mat.

DE 40 13 645 A1 discloses an air filter for an electronics housing,which is constructed such that an exchanging of the filter mats is to bepossible without interrupting the operation of the apparatus. To dothis, the air filter has a filter mat by means of which dust andimpurities are able to be removed from an air current which is drawn infrom the outside, and a support in which the filter mat is mounted andwhich comprises a holding frame and a handle for manipulating thesupport. Furthermore, holding arrangements are provided for the engaginghold of the support in/on the housing with a tight closure with respectto ventilation openings of the housing and guide arrangements, which aremounted on the housing such that the support is movable through aninsertion opening in the housing along the guide arrangements to theholding arrangements and out again and is able to be engaged into theholding arrangements.

On the one hand, the filter fan mounts a specially constructed housing,so that the air current can be directed at an angle from the inlet tothe outlet through the interior of the housing, which has a separate,closable maintenance opening, in order to be able to grasp hold of thefilter mat through the maintenance opening in order to exchange it,whilst on the other hand the air filter housing is provided with amaintenance opening in order to be able to exchange via the latter thefilter mat which is constructed in the manner of a cassette.

SUMMARY OF THE INVENTION

It is an object of the present invention to construct an air passagedevice according to the type described in the introduction so that it ispossible to quickly exchange the filter mats without tools and withoutgreat structural expenditure, and to open the fan grid effortlessly bythe pressure of a finger.

In accordance with the invention, at least one swivellable sheet orlamella element or at least one flexible tongue-shaped side wall sectionseparated from the remaining side wall surface by slits runningtransversely to the longitudinal direction of the side wall is formed inthe region of the upper side wall of the design cover facing away fromthe swivel axis for swivelling the design cover, wherein the sheetelement and the tongue-shaped side wall section are formed as a detentconnection between the design cover and the base housing wherein thedetent connection can be operated by a finger, is detachable and able tobe locked.

A first embodiment of the invention consists in that at least one sheetelement, preferably the uppermost sheet element, or a section of thesheet element or a sheet element only connected with the upper side wallof the design cover with its longitudinal edge, of the fan grid isswivellably arranged about a rotation axis running in the longitudinaldirection of the sheet element in the fan grid, and is constructed as anactuating element, able to be operated by a finger, for an arrestingarrangement for locking and releasing a locking arrangement between thefan grid and the base housing.

Through the fact that the design cover with the fan grid together withthe filter mat is held swivellably on the base housing of the airpassage device, it is possible to exchange the filter mats effortlessly,because the design cover is simply opened up and swivelled so that thefilter mat is freely accessible to be exchanged. By opening the designcover, the maintenance opening is provided for exchanging the filtermat, whereby the construction of a separate maintenance opening in thefan housing is dispensed with.

A further advantage consists in that the opening and closing of thedesign cover takes place by means of a sheet element of the fan grid ora side wall of the design cover. The sheet element is thereforeconstructed as an actuating element which is able to be operated by afinger for the arrangement for locking and releasing a lockingarrangement between the design cover or the fan grid and the basehousing.

In order to be able to actuate the said sheet element, according to oneembodiment, the latter is preferably held swivellably about itslongitudinal axis in the side walls of the design cover or fan grid.Alternatively, the sheet element can be interrupted laterally, in whichthen the longitudinal axis in the region of the connection to the basehousing serves as a swivelling hinge, when this sheet element is formedon the base housing, with this connection region also being able to beformed as a film hinge; however, the use of a flexibly elastic materialsuch as plastic is sufficient in order to make possible a swivelling ofthe sheet element.

This operable sheet element of the fan grid has a detent cam in theregion of its longitudinal edge facing the base housing and facing awayfrom the swivel axis of the fan grid on the base side, which detent camis able to brought into operative connection for the formation of adetent connection in operative connection with a detent element, forexample in the form of a hook or in the manner of a recess. On closingthe design cover or fan grid, the elements of the closure arrangementengage reciprocally, so that the filter mat is held securely between thefan grid and the base housing.

The development of the detent connection is not exclusively limited tothe upper longitudinal edge of the swivellable sheet element. Theindividual elements for the detent connection can be arranged both onthe longitudinal edge of the swivellable sheet element centrally oreccentrically, in which in the latter case one or more detentconnections can then be provided, which are constructed and arranged sothat the detent connections are constructed in the region of the lateralwall surfaces of the design cover.

A further development of the invention makes provision that in the sidewall facing the uppermost sheet element of the fan grid, a wall sectionis formed by slits running transversely to the longitudinal direction ofthe side wall, on which wall section an unconnected sheet element isformed with its longitudinal edge in the opposite side walls of thedesign cover, in which in the region of the forming on of the sheetelement on the side wall section of the side wall of the design cover,the longitudinal axis LA lies for the swivelling of the side wallsection on operation by finger of the sheet element. In this embodimentalso the connection region between the side wall and the sheet elementforms the swivel axis for the side wall section in order to be able toswivel it.

A tool-free exchanging of the filter mat is therefore possible, so thatthe filter mats can also be exchanged when the air passage device is inthe installed state. By external actuation of the swivellable sheetelement, an effortless opening of the design cover is possible to freethe filter mat for removal. After the filter mat has been exchanged, thedesign cover is merely swivelled towards the base housing of the airpassage device, so that the detent connection is produced and thereceiving space for the filter mat is closed.

A second embodiment of the invention consists in that in the side wallof the design cover facing away from the swivel axis for swivelling thedesign cover, at least one elastic, tongue-shaped side wall section isformed, separated from the remaining side wall surface by slits runningtransversely to the longitudinal direction of the side wall, which sidewall section is flexibly elastic and has a restoring capacity due to thematerial of which the design cover consists, in which the tongue-shapedside wall section is held by means of a cross-piece in the side wall andhas an engagement element in the region of its free end for theproduction of a detachable detent connection between the design coverand the base housing, which engagement element is able to be broughtinto operative connection with a holding element which is mounted orformed on the side wall of the base housing which corresponds to theside wall of the design cover.

By this embodiment of the invention, it is also achieved that the designcover with the fan grid is held together with the filter mat swivellablyon the base housing of the air passage device, so that an exchanging ofthe filter mats can be carried out effortlessly, because the designcover is simply opened out and swivelled, so that the filter mat isfreely accessible for exchanging. By opening the design cover, themaintenance opening is provided for the exchange of the filter mat,whereby the construction of a separate maintenance opening in the fanhousing is dispensed with.

A further advantage consists in that the opening and closing of thedesign cover is simplified in that the side wall of the design cover,facing away from the swivel axis of the design cover, has at least oneflexibly elastic tongue-shaped section formed from the side wallmaterial, which is provided with an engagement element which, on closingof the design cover, engages into a holding element which is formed orconstructed on the side wall of the base housing corresponding to theside wall of the design cover having the tongue-shaped side wallsection, so that on closing of the design cover, the engagement elementof the tongue-shaped side wall section engages or catches into theholding element. In this process, the bent, tongue-shaped side wallsection springs back into its initial position, so that the design coveris locked with the base housing. For unlocking, the design cover iswithdrawn from the base housing, whereby the detent connection isreleased.

A tool-free changing of the filter mats is therefore likewise possibleso that the filter mats can also be changed when the air passage deviceis in the installed state. By external actuation of the flexiblyelastically constructed section in the upper side wall of the designcover, an effortless opening of the design cover is possible to free thefilter mat for removal. After the filter mat has been exchanged, thedesign cover is merely swivelled towards the base housing of the airpassage device, so that the detent connection is produced and themounting space for the filter mat is closed.

A further embodiment of the invention makes provision that for theproduction of the detachable detent connection between the design coverand the base housing, at least one of the side walls of the frame of thedesign cover has at least one flexible, tongue-shaped side wall sectionformed from the material of the side wall, which side wall section isconnected on one end side via a cross-piece with the side wall and isheld therein, and which at its free end has a detent cam as engagementelement, which is able to be brought into operative connection with aholding element which is provided in the side wall of the base housing,corresponding to the side wall of the design cover.

Here, the flexible tongue-shaped side wall section is formed by twolongitudinal slits running transversely to the longitudinal direction ofthe side wall of the frame of the design cover, the length of whichslits is smaller than the width of the side wall.

In the upper regions or in the side walls of the design cover and/or ofthe base housing, at least one tongue-shaped side wall section and atleast one holding element, corresponding to the tongue-shaped side wallsection, are provided in the respective side walls of the frames of thedesign cover and of the base housing.

Preferably, the tongue-shaped side wall section and the holding elementcorresponding thereto are arranged centrally on the side walls of theframes of the design cover and of the base housing.

According to a further embodiment of the invention, in the upper regionsor in the side walls of the design cover and of the base housing,corresponding to each other, two tongue-shaped side wall sections andtwo holding elements, corresponding to the tongue-shaped side wallsections, are provided in the respective side walls of the frames of thedesign cover and of the base housing.

Furthermore, each tongue-shaped side wall section has at its free end asection bent at right-angles, which engages in or behind acorrespondingly formed slit-shaped recess or opening in thecorresponding side wall of the frame of the base housing, as a holdingelement.

A further embodiment provides an air passage device in which eachtongue-shaped side wall section of the design cover has a detent cam inthe region of its free end, in which on the underside of the side wallof the base housing overlapping the side wall of the design cover, adepression is provided which is formed accordingly corresponding to theshape of the detent cam.

A detent connection which is constructed in such a way provides theadvantage that the opening and closing of the design cover is simplifiedin that the side wall of the design cover, facing away from the swivelaxis of the design cover, has at least one flexibly elastictongue-shaped section formed from the side wall material, having adetent cam which, on closing of the design cover, engages into a recessor depression which is formed on the underside of the side wall of thebase housing corresponding to the side wall of the design cover havingthe tongue-shaped section, so that on closing of the design cover, thetongue-shaped side wall section is bent until the detent cam engagesinto the depression on the side wall of the base housing, in which thenthe tongue-shaped section springs back into its initial position untilthe detent cam is fully engaged into the depression, so that the designcover is locked with the base housing. For unlocking, the tongue-shapedside wall section is bent downwards, for example by acting upon by apointed object, so that the design cover is withdrawn from the basehousing, in which the detent cam of the base housing moves out from thedepression on the side wall of the base housing, in which, owing to theflexibly elastic construction of the tongue-shaped side wall section,the latter is bent slightly on the side wall of the base housing, sothat the detent cam can slide out from the depression.

Furthermore, provision is made that the design cover is swivellablyarranged on any desired side wall of the frame of the base housing, inwhich the detent connection for the design cover and the base housing isprovided on the side walls of the design cover, lying opposite theswivel axis for the design cover, and the base housing.

A further embodiment makes provision that to produce the detachabledetent connection between the design cover and the base housing, in atleast one of the side walls of the frame of the base housing at leastone flexible tongue-shaped side wall section is formed from the materialof the side wall, separated from the remaining side wall surface byslits running transversely to the longitudinal direction of the sidewall, in which the tongue-shaped side wall section is held in the sidewall by means of a cross-piece and on the inner wall side has a holdingelement in the form of a preferably circular depression or opening, boreor blind-end bore, which is able to be brought into operative connectionwith an engagement element in the form of a detent cam, which isarranged or formed on the side wall of the design cover corresponding tothe side wall of the base housing having the holding element, in whichthe detent cam is preferably provided at its free end with a sectionwhich is partially formed or running in an encircling manner conicallyto the detent cam end, as a sliding surface.

The invention therefore consists of a connection system for the designcover and the base housing of the air passage connection, which can bereleased by the pressure of a finger to open the design cover to changethe filter mat, and is constructed so that on closing of the designcover, the latter engages into the base housing.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of the disclosure. For a better understanding of the invention, itsoperating advantages, specific objects attained by its use, referenceshould be had to the drawing and descriptive matter in which there areillustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a diagrammatic exploded illustration of the air passage deviceaccording to a first embodiment of the invention, consisting of a frontdesign cover with a fan grid and with a filter mat, a base housing forthe design cover and for a ventilator and with a sheet elementconstructed as an actuating element able to be actuated by a finger, foran arresting arrangement for locking and releasing a detent-like lockingarrangement between the fan grid or design cover and the base housing ofthe air passage device,

FIG. 2 is a diagrammatic illustration of the base housing with foldedopen design cover and with a filter mat of the air passage deviceaccording to FIG. 1, lying between the base housing and the designcover,

FIG. 3 is a vertical sectional view through the air passage device,

FIG. 4 is in a front view the fan grid of the design cover with sheetelements,

FIG. 5 is a diagrammatic rear view of the design cover with the fangrid,

FIG. 6 shows a section of the fan grid of the design cover with a sheetelement constructed as operating element, in an enlarged diagrammaticillustration,

FIG. 7 shows in a diagrammatic view the swivellable sheet element,constructed as operating element, with the arresting device for thedetachable fastening of the design cover on the base housing of the airpassage device,

FIG. 8 is a rear view of the design cover with a side wall constructedas operating element for the arresting device,

FIG. 9 is an enlarged view from above onto the design cover with theside wall constructed as an operating element,

FIG. 10 is a diagrammatic exploded illustration of the air passagedevice according to a second embodiment of the invention, consisting ofa design cover with a fan grid and with a filter mat and a base housingfor the design cover for a ventilator and with a flexible andtongue-shaped side wall section of the design cover constructed as afinger-actuatable actuating element for an arresting arrangement forlocking and releasing a detent-like locking arrangement between the fangrid or design cover and the base housing of the air passage device,

FIG. 11 is a diagrammatic illustration of the base housing with thedesign cover folded open and with a filter mat of the air passage deviceaccording to FIG. 10 arranged between the base housing and the designcover,

FIG. 12 is a front view of the air passage device,

FIG. 13 is a vertical sectional view through the air passage device,

FIG. 14 is a diagrammatic rear view of the design cover with a flexible,tongue-shaped side wall section in the upper side wall of the frame ofthe design cover as operating element for the production of a detentconnection between the design cover and the base housing of the airpassage device, in which the tongue-shaped side wall section has at itsfree end an engagement element in the form of a detent cam,

FIG. 15 is an enlarged view from above onto the design cover with thetongue-shaped side wall section, having the detent cam, formed in theupper side wall of the design cover,

FIG. 16 is an enlarged view from above onto the base housing with theholding element, formed on the underside of the upper side wall, in theform of a depression for the engagement of the detent cam on thetongue-shaped side wall section,

FIG. 17 is an enlarged diagrammatic side view of a section of the designcover with the flexible, tongue-shaped side wall section, which carriesat its free end the detent cam which engages into the depression on theunderside of the side wall of the base housing,

FIG. 18 is an enlarged diagrammatic side view of a section of the basehousing with the depression, formed in the side wall of the basehousing, to receive the detent cam,

FIG. 19 is an enlarged view from above onto the design cover with twoformed in the upper side wall of the design cover with engagementelements, carrying at their ends, in the form of detent cams to producethe detent connection between the design cover and the base housing ofthe air passage device,

FIG. 20 is an enlarged view from above onto the base housing with twoholding elements provided in the upper side wall of the base housing, inthe form of slit-shaped openings for the engagement of the engagementelements on the tongue-shaped side wall sections of the design cover,

FIG. 21 is a diagrammatic rear view onto the base housing of the airpassage device,

FIG. 22 is a diagrammatic view onto the base housing of the air passagedevice with holding elements, formed as depressions, in flexible,tongue-shaped side wall sections formed in the upper side wall,

FIG. 23 is an enlarged diagrammatic view of the upper section of thebase housing according to FIG. 22,

FIG. 24 is an enlarged diagrammatic view of a part of the upper sectionof the base housing according to FIG. 22,

FIG. 25 is an enlarged diagrammatic view of the upper section of thebase housing with a view from below onto the side wall having thetongue-shaped side wall sections,

FIGS. 26 and 26A are enlarged diagrammatic views of engagement elementsconstructed as detent cams.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The air passage device 200 illustrated in FIG. 1 to 3 of a firstembodiment of the invention is able to be used in connection with a fanor ventilator as a filter fan and without a fan 20 as an outlet filter.The air passage device 200 is used in housings of components generatingwaste heat, such as switch boxes, electronics boxes, computer systems orsuchlike, in which the air passage device 200 is incorporated inmounting openings 50 in a wall 51 of such a housing (FIG. 3).

The essential components of the air passage device 200 are a designcover 80 with a fan grid 10 with ventilation slits, which forms thefront covering device 100 for a base housing 21, a fan support 25 forthe fan 20, when the air passage device 200 is used as a filter fan(FIG. 1 to 3).

The covering device 100, which forms the fan grid 10, is constructed asa design cover 80 and consists of a frame-like housing 30, preferablywith side walls 30 a, 30 b, 30 c, 30 d and with sheet elements 90, inwhich ventilation slits are formed between the sheet elements 90 whichpartially overlap each other. The filter mat 60 can be held against theinner wall surface of the fan grid 10 in the design cover 80 (FIG. 3),or it is inserted into the base housing 21, which is closed by means ofthe design cover 80. The sheet elements 90 are held in two opposite sidewalls 30 b, 30 d of the frame-like housing 30 of the design cover 80, orare formed onto these side walls (FIG. 4).

The covering device 100 with the fan grid 10 consists of the frame-likehousing 30 which receives the filter mat 60, a fan grid 10, heldsecurely, detachably or swivellably in the housing 30 and covering thefilter mat 60, forming the design cover 80. This fan grid 10 comprisesat least two lateral side walls 30 b, 30 d extending on the edge side ina longitudinal direction, preferably constructed in the form of cheekpieces, between which the sheet elements 90 are arranged (FIGS. 4, 5 and8). The sheet elements 90 are arranged at a distance from each other,with partial overlapping at the same time, and are placed obliquely suchthat the respective front and outer sheet edges 91 are situated lowerwith respect to the rear sheet edges 92. The upper rear sheet edges 92preferably have profilings 95 formed in the manner of a barb or hook(FIG. 6), in order to prevent the penetration of water and in order todivert away water acting on the design cover 80.

The design cover 80 holding the filter mat 60, or the fan grid 10, isswivellable about its swivel axis 26 on the base side in arrow directionX for opening the mounting chamber for the filter mat between the fangrid 10 and the base housing 21 (FIG. 2). The arresting of the fan grid10 on the base housing 21 preferably takes place in the upper region,e.g. by means of an arresting device 40, preferably of the components96, 97 which are constructed as detent cam and engagement elements(FIGS. 2 and 7).

The actuation of the arresting device 40 takes place by means of sheetelements 90′ or a sheet element 90″ of the sheet elements 90 of the fangrid 10. In the embodiment shown in FIGS. 6 and 7, the uppermost sheetelement 90′ is constructed as an actuating element. To do this, thesheet element 90′ is held swivellably in the two side walls 30 b, 30 dof the frame-like frame 30 in the arrow direction X1, such that thesheet element 90′ is swivellable about its longitudinal axis 90 a asswivel- and rotation axis (FIGS. 6 and 7). Preferably, the sheet element90′ is swivellable about a swivel axis 90 a running centrally in thelongitudinal direction of the sheet element 90′. The upper, rear sheetedge 92 is then provided with the components of the arresting device 40,in which the arresting device is formed or fastened centrally on thesheet element 90′; however, an eccentric arrangement is also possible(FIG. 7). The possibility also exists of providing the arresting device40 at one end or at both ends of the sheet element 90′, so that thecomponents of this device are then provided respectively at the endregions of the sheet element 90′ and on the respective opposite wallsurfaces of the base housing 21, so that the components can engage intoeach other for locking.

At least one sheet element 90′ and in fact preferably the respectiveuppermost sheet element of the fan grid 10 is held swivellably therein.By finger actuation, the sheet element 90′ is swivelled so that thearresting or locking between the fan grid 10 and the base housing 21 isreleased, so that on swivelling of the fan grid in the arrow direction Xoutwards, the filter mat 60 is freed for removal (FIG. 2). When thedesign cover 80 and the base housing 21 are folded together, thecomponents of the arresting device 40 then engage into each other.

The arresting device 40 formed on the design cover 80 and the basehousing 21 has, for example, on the co-swivelling longitudinal edge 90 aof the sheet element 90′ on its actuation a detent cam 96 which is ableto be brought into operative connection with a hook-shaped orrecess-like detent element 97 to form a detent connection, so that onclosing of the design cover 80, the detent cam 96 engages into itscounter-element, whereas the possibility also exists that also withnon-actuation of the sheet element 90′ on closing of the design cover80, the detent connection is produced. To open the detent connection,the sheet element 90′ is then swivelled with a finger actuation, inwhich the detent cam 96 is swivelled out from its engagement position onthe base housing 21 and frees the design cover 80 for swivelling intothe filter removal position (FIG. 2).

A further embodiment of the invention makes provision that only onesection 90′a of the uppermost sheet element 90′ is constructed so as tobe swivellable about a rotation axis DA in the fan grid 10, running inthe longitudinal direction of the sheet element 90′ (FIG. 5).

In the embodiment of an air passage device shown in FIGS. 8 and 9, inthe side wall 30 a facing the uppermost sheet element 90″ of the designcover 80 formed with its longitudinal edge on the upper side wall 30 aof the frame-like housing 30 of the design cover 80, a side wall section35 is formed by slits 32, 33 running transversely to the longitudinaldirection of the side wall, which side wall section 35 is swivellableabout its longitudinal axis LA in the region of its forming 36 on thefan grid 10. This side wall section 35 carries at least one detent cam96 which is able to be brought into engagement with an opening 97′ onthe side wall 21 a of the housing 21, corresponding to the side wall 30a of the fan grid 10, to form the detent connection (FIG. 1). Theactuation of the side wall section 35 takes place in this embodiment bymeans of the sheet element 90″, which is formed in the upper region ofthe design cover 80. This side wall section 35 of the frame-like housing30 of the design cover 80 is formed with its longitudinal edge on thesheet element 90″ which, however, is not connected by its end regionswith the opposite side walls 30 b, 30 d of the design cover 80 (FIG. 6).The longitudinal axis LA for the swivelling of the side wall section 35with finger actuation of the sheet element 90″ lies in the region ofthis forming on of the sheet element 90″ on the side wall section 35 ofthe side wall 30 a of the design cover 80. This longitudinal axis LA is,at the same time, the rotation axis. By raising the sheet element 90″,the side wall section 35 which is securely connected therewith is movedso that the detent connection can be opened. Owing to the use offlexibly elastic plastic, the swivelling of the sheet element 90″ andthe production of the detent connection is possible by the detent cam(s)96 on the side wall section 35 engaging into the openings or recesses97′ on the side wall 21 a of the housing 21, when the design cover 80 isdetachably connected together with the housing 21.

The air passage device 200 of the second embodiment of the invention,illustrated in FIG. 10 to 12, is able to be used in connection with afan or ventilator as a filter fan, and without a fan 20 as an outletfilter. The air passage device 200 is used in housings of componentsgenerating waste heat, such as switch boxes, electronics boxes, computersystems or suchlike, in which the air passage device 200 is installed inmounting openings 50 in a wall 51 of such a housing (FIG. 12).

The essential components of the air passage device 200 are a designcover 280 with a fan grid 210 with ventilation slits, which forms thefront covering device 100 for a base housing 221 and a fan support 25for the fan 20, when the air passage device 200 is used as a filter fan(FIG. 10 to 12).

The covering device 100, which forms the fan grid 210, is constructed asdesign cover 280 and consists of a frame 230 with side walls 230 a, 230b, 230 c, 230 d and in the embodiment illustrated in the drawing withsheet elements 90, in which ventilation slits are formed between thepartially overlapping sheet elements 90. The filter mat 60 is heldagainst the inner wall surface of the fan grid 210 in the frame of thedesign cover 280 (FIG. 12) or it is inserted into the base housing 221,which is closed by means of the design cover 280. The sheet elements 90are held in two opposite side walls 230 b, 230 d of the frame 230 of thedesign cover 280 or are formed onto these side walls (FIG. 13). Thedesign cover 280 is swivellable about the swivel axis 226, in order tobe able to open the design cover for the removal of the filter mat 60.The design cover 280 can also be constructed in the form of a grid.

The covering device 100 with the fan grid 210 therefore consists of theframe 230 which holds the filter mat 60, a fan grid 210, held securely,detachably or swivellably in the frame 230 and covering the filter mat60, which fan grid 210 forms the design cover 280. This fan grid 210comprises at least two lateral side walls 230 b, 230 d, extending on theedge side in a longitudinal direction, preferably constructed in theform of cheek pieces, between which side walls 230 b, 230 d the sheetelements 90 are arranged (FIGS. 13 and 14). The sheet elements 90 arearranged at a distance from each other, partially overlapping each otherat the same time, and are placed obliquely such that the respectivefront and outer sheet edges 91 are placed lower with respect to the rearsheet edges 92.

The design cover 280 receiving the filter mat 60, or the fan grid 210,is swivellable in the arrow direction X about its swivel axis 226 on thebase side for opening the mounting chamber, formed by the frame 230, forthe filter mat between the fan grid 210 and the base housing 221 (FIG.11). The arresting of the fan grid 210 on the base housing 221preferably takes place in the upper region e.g. by means of a detent- orarresting device 240, preferably of the components 296, 297 which areconstructed as engagement element and as holding element (FIGS. 10,11,15and 16). The base housing 221 consists of a grid wall 325 and a frame321 formed thereon with the side walls 221 a, 221 b, 221 c, 221 d. Ifthe design cover 280 is folded out onto the base housing 221, then theside walls 230 a, 230 b, 230 c, 230 d of the design cover 280 come tolie against the inner wall surfaces of the side walls 221 a, 221 b, 221c, 221 d of the frame 321 of the base housing 221, i.e. the side wallsof the frame of the base housing 221 overlap the side walls of the frameof the design cover 280, so that the side walls 230 a and 221 a, 230 band 221 b, 230 c and 221 c and 230 d and 221 d correspond to each other.

The design cover 280 therefore engages with its encircling side walls230 a, 230 b, 230 c, 230 d into the encircling side walls 221 a, 221 b,221 c, 221 d of the base housing 221, so that in the folded togetherstate, the design cover 280 lies on the base housing 221 and is held byit, in which the side walls 231 a, 221 a of the design cover 280,respectively facing away from the swivel axis 226 of the design cover280, and of the base housing 221 lie on each other. The side wall 221 aof the base housing 221 overlaps here the side wall 230 a of the designcover 280.

The detent connection 240 (FIGS. 15 and 16), by means of which thedesign cover 280 is detachably held on the base housing 221, consists ofat least one flexible, tongue-shaped side wall section 235 formed in theside wall 230 a of the design cover 280, which is formed by means ofslits 232, 233 in the side wall 230 a, running transversely to thelongitudinal direction of the side wall. This tongue-shaped side wallsection 235 is held in a flexibly elastic manner on a cross-piece 238 ofthe side wall 230 a of the design cover 280, so that this tongue-shapedside wall section 235 can avoid a pressure exerted onto the side wallsection 235 and, on relief of pressure, can spring back into its initialposition (FIGS. 14, 15 and 16).

The flexibly elastic development of the tongue-shaped side wall section235 of a bent position into the initial position is achieved by thematerial which is used for the production of the design cover 280, whichis plastic or a metal, in which the materials must have flexibly elasticproperties.

The tongue-shaped side wall section 235 has an engagement element 296 onthe outer wall side, e.g. in the form of a detent cam 245, whichcooperates with a holding element 297 which is formed on the undersideof the side wall 221 a of the base housing 221. This holding element 297is formed for example as a depression or recess 239 with a shape whichcorresponds to the shape of the detent cam 245. This detent cam 245 hasa shape corresponding to the depression 239, so that when the designcover 280 is closed, the detent cam 245 engages into the depression 239in the side wall 221 a of the base housing 221, so that the design cover280 is locked with the base housing 221. Instead of a depression 239, anopening may also be provided in the side wall 221 a of the base housing221, into which the detent cam 245 engages on closing of the designcover 280. The depression 239 may furthermore also be constructed in ahemispherical shape or as a blind-end bore. Through the fact that thetongue-shaped side wall section 235 is flexibly elastic, the latter,when the detent cam 245 is moved towards the depression 239 on closingof the design cover 280, is bent downwards and springs back into itsinitial position owing to its restoring capacity, i.e. into the planeformed by the side wall 230 a, when the detent cam 245 comes to lie inthe depression 239 (FIGS. 15, 16, 17 and 18).

In the example embodiment illustrated in the drawing, the detentconnection 240 of the two components 296, 297 is provided centrally inthe side walls 221 a, 230 a of the base housing 221 and of the designcover 280. The number of detent connections 240 can, however, beselected as desired; it is determined in each case by the size of theair passage device.

When the design cover 280 is folded into the base housing 221, then thetwo side walls 221 a and 230 a lie one over the other, so that theengagement element 296 is in operative connection with holding element297. If the detent connection 240 between the engagement element 296 andthe holding element 297 is to be released to open the design cover 280,then the tongue-shaped side wall section 235 in the side wall 230 a ofthe design cover 280 must be bent towards the swivel axis 226 of thedesign cover 280, so that the engagement element 296, i.e. the detentcam 245, is moved out from the depression 239 in the side wall 221 a ofthe base housing 221. This bending may take place for example by meansof a pin-like object, such as for example a screwdriver. In order tomake this possible, the side wall 221 a of the base housing 221 can beprovided with a slit-shaped recess or opening 330, which is arrangedabove the tongue-shaped side wall section 235 in the side wall 221 a ofthe base housing 221, so that the actuating object is guided through theopening 330 and, with a downwards movement in the arrow direction X, ispressed against the tongue-shaped side wall section 235, whereby thelatter is bent in the arrow direction X1 (FIGS. 17, 18 and 21).

In the embodiment according to FIGS. 20 and 21, two tongue-shaped sidewall sections 235 are provided in the upper regions or in the side walls221 a, 230 a of the design cover 280 and of the base housing 221, andtwo holding elements 297 corresponding to the tongue-shaped side wallsections 235 are provided in the respective side walls 230 a, 221 a ofthe frames 230, 321 of the design cover 280 and of the base housing 221.

The two tongue-shaped side wall sections 235 are likewise constructed soas to be flexibly elastic and are connected via the cross-pieces 238with the material of the design cover 280. At their free ends, thetongue-shaped side wall sections 235 have sections 245′ bent atright-angles, which form the engagement elements 296 (FIG. 19). When thedesign cover 280 is closed, these bent sections 245′ engage intoslit-shaped recesses or depressions or openings 239′, which are providedin the side wall 221 a of the base housing 221 corresponding to the sidewall 230 a of the design cover 280 (FIG. 20).

The preceding example embodiments assume that the detent connection 240is provided with respect to the swivel axis for the design cover 280,i.e. in the upper region of the air passage device. However, provisionis made according to the invention that the design cover 280 isswivellably arranged on any desired side wall 221 a, 221 b, 221 c, 221 dof the frame 321 of the base housing 221, in which the detent connection240 for the design cover 280 and the base housing 221 is provided on theside walls of the design cover 280, lying opposite the swivel axis forthe design cover 280, and the base housing 221.

In the embodiment according to FIG. 22 to 25, to produce the detachabledetent connection 240 between the design cover 280 and the base housing221 of the air passage device in the upper side wall 221 a of the frame321 of the base housing 221, two flexible tongue-shaped side wallsections 235 are formed from the material of the side wall 221 a,separated from the remaining side wall surface by slits 232, 233 runningtransversely to the longitudinal direction of the side wall. Eachtongue-shaped side wall section 235 is held by means of a cross-piece238 in the side wall 221 a. The tongue-shaped wall section 235 isprovided on the inner wall side with a holding element 297 in the formof a preferably circular depression 239 or opening, bore or blind-endbore. This depression 239 is able to be brought into operativeconnection with an engagement element 296 of the design cover 280 in theform of a detent cam 245. This detent cam 245 is arranged or formed onthe side wall 230 a of the design cover 280, which corresponds to theside wall 221 a of the base housing 221 having the holding element 297.The detent cam 245 has at its free end a section 245 a running conicallytoward the detent cam end (FIGS. 26 and 26A). Instead of a chamferedsection 245 a, the detent cam 245 may also have an encircling sectionrunning conically to the detent cam end 245 b.

In the previously described embodiment, the side walls 221 a, 230 a eachhave two tongue-shaped side wall sections 235 with holding elements 297and engagement elements 296 corresponding thereto. The detent connection240 may also be produced with a holding element 297 and an engagementelement 296.

The cooperation of the holding elements 297 with the engagement elements296 takes place as follows in an embodiment according to FIG. 22 to 25:When the design cover 280 is opened and is folded onto the base housing221, then the tongue-shaped side wall section 235 of the side wall 221 aof the base housing 221 slides over the detent cam 245 of the side wall230 a of the design cover 280, in which the tongue-shaped side wallsection 235, owing to its flexible characteristic is slightly raised, sothat the free end of the tongue-shaped side wall section 235 slides overthe detent cam 245. This sliding movement is assisted by the chamferedsection 245 a at the end of the detent cam 245. The tongue-shaped sidewall section 235 slides, on closing of the design cover 280, so far overthe detent cam 245 until the detent cam 245 engages into the depression239 on the underside of the tongue-shaped side wall section 235. Thisengaging is assisted by the restoring capacity of the tongue-shaped sidewall section 235 from the bent position into the initial position, i.e.into the plane of the side wall 221 a of the base housing 221. In theclosed state, the design cover 280 lies against the base housing 221, inwhich the encircling side walls 221 a, 221 b, 221 c, 221 d of the basehousing overlap the encircling side walls 230 a, 230 b, 230 c, 230 d ofthe design cover 280.

The opening of the design cover 280 takes place by a tug-like withdrawalof the design cover from the base housing, in which the detent cam 245slides out from the depression 239. This withdrawal is assisted by aconical marginal shaping of the depression 239 and by the chamfered endsection 245 a of the detent cam 245.

While specific embodiments of the invention have been described indetail to illustrate the inventive principles, it will be understoodthat the invention may be embodied otherwise without departing from suchprinciples.

1. An air passage device, particularly a filter fan or outlet filter,with a fan (20) or without a fan, for installation into a mountingopening (50) in a wall (51), particularly of a housing for componentsgenerating waste heat such as a switch box, electronics box, computersystem or suchlike, wherein the air passage device (200) comprising abase housing (21; 221) with or without a fan support (25) and with anencircling frame (321) of side walls (21 a, 21 b, 21 c, 21 d; 221 a, 221b, 221 c, 221 d) and a design cover (80; 280) with an encircling frame(30; 230), formed on an air outlet side, of side walls (30 a, 30 b, 30c, 30 d; 230 a, 230 b, 230 c, 230 d), which engages with its side wallsinto the side walls of the frame (321) of the base housing (21; 221) andwhich holds a filter mat (60), wherein the design cover (80; 280) has onan air inlet side a covering device (100) constructed as a fan grid (10;210) with sheet elements (90, 90′; 290, 290′) preferably held on twoopposite side walls of the design cover (80; 280), and wherein thedesign cover (80; 280) is arranged on the base housing (21; 221) about ahorizontal or vertical swivel axis (26; 226) to free a removal opening(29) for the removal or introduction of the filter mat (60) for thepurpose of exchanging a filter mat, wherein at least one swivellablesheet element (90) or at least one flexible, tongue-shaped side wallsection (235), separated from the remaining side wall surface by slits(332, 333) running transversely to the longitudinal direction of theside wall, is formed in the region of the upper side wall of the designcover (80; 280) facing away from the swivel axis (26; 226) forswivelling the design cover (80; 280), wherein the sheet element (90)and the tongue-shaped side wall section (235) are formed between thedesign cover (80; 280) and the base housing (21; 221) as a detachableand lockable detent connection (40; 240), that can be operated by afinger.
 2. An air passage device, according to claim 1, wherein at leastone sheet element (90), preferably the uppermost sheet element (90′), ora section of the sheet element (90′) or a sheet element (90″) onlyconnected with the upper side wall (30 a) of the design cover (80) withits longitudinal edge, of the fan grid (10) is swivellably arrangedabout a rotation axis (DA) running in the longitudinal direction of thesheet element in the fan grid (10), and is constructed as an actuatingelement (95), able to be operated by a finger, for an arrestingarrangement (40) for locking and releasing a locking arrangement betweenthe fan grid (10) and the base housing (21).
 3. The air passage deviceaccording to claim 1, wherein in the side wall (230 a, 221 a) of thedesign cover (280), facing away from the swivel axis (226) forswivelling the design cover (280), or of the base housing (221), atleast one flexible, tongue-shaped side wall section (235) is formed,separated from the remaining side wall surface by slits (232, 233)running transversely to the longitudinal direction of the side wall,which side wall section (235) is flexibly elastic and has a restoringcapacity owing to the material of which the design cover (280) consists,wherein the tongue-shaped side wall section (235) is held in the sidewall (230 a) by means of a cross-piece (238) and in the region of itsfree end has an engagement element (296) to produce a detachable detentconnection (240) between the design cover (280) and the base housing(221), which engagement element (296) is able to be brought intooperative connection with a holding element (297) which is provided onthe side wall (221 a) of the base housing (221), which corresponds tothe side wall (230 a) of the design cover (280).
 4. The air passagedevice according to claim 1, wherein the uppermost sheet element (90′)of the fan grid is held swivellably about its longitudinal axis (LA) onthe side walls (30 b, 30 d) of the design cover (80).
 5. The air passagedevice according to claim 1, wherein a section (90′a) of the uppermostsheet element (90′) of the fan grid (10) is constructed in the sheetelement (90′) swivellably about a rotation axis (DA) running in thelongitudinal direction of the sheet element (90′).
 6. The air passagedevice according to claim 1, wherein in the side wall (30 a) facing theuppermost sheet element (90′) of the fan grid (10), a side wall section(35) is formed by slits (32, 33) running transversely to thelongitudinal direction of the side wall, on which side wall section (35)an unconnected sheet element (90″) is formed with its longitudinal edgein the opposite side walls (30 b, 30 d) of the design cover (80),wherein in the region of the forming on of the sheet element (90″) onthe side wall section (35) of the side wall (30 a) of the design cover(80), the longitudinal axis (LA) lies for the swivelling of the sidewall section (35) on operation by finger of the sheet element (90″). 7.The air passage device according to claim 1, wherein the uppermost sheetelement (90, 90′) or a sheet element section in the region of itslongitudinal edge (90 a) facing the base housing (21) and facing awayfrom the swivel axis (26) of the fan grid (10) on the base side, has atleast one detent cam (96) which is able to be brought into operativeconnection for the formation of a detent connection in operativeconnection with at least one hook-shaped or recess-like detent element(97).
 8. The air passage device according to claim 1, wherein theswivellable side wall section (35) of the side wall (30 a) of the designcover (80) has at least one detent cam (96) which is able to be broughtinto operative connection for the formation of a detent connection inoperative connection with at least one hook-shaped or recess-like detentelement (97).
 9. The air passage device according to claim 1, wherein toproduce the detachable detent connection (240) between the design cover(280) and the base housing (221) at least one of the side walls (230 a,230 b, 230 c, 230 d) of the frame (230) of the design cover (280) has atleast one flexible tongue-shaped side wall section (235) formed from thematerial of the side wall (230 a, 230 b, 230 c, 230 d), which isconnected on one end side via a cross-piece (238) with the side wall(230 a, 230 b, 230 c, 230 d) and is held therein, and which at its freeend has a detent cam (245) as engagement element (296), which is able tobe brought into operative connection with the holding element (297),which is provided in the side wall (221 a) of the base housing (221),which corresponds to the side wall (230 a) of the design cover (280).10. The air passage device according to claim 1, wherein the flexible,tongue-shaped side wall section (235) is formed by two longitudinalslits (232, 233) running transversely to the longitudinal direction ofthe side wall (230 a) of the frame (230) of the design cover (280), thelength of which slits (232, 233) is smaller than the width of the sidewall (230 a).
 11. The air passage device according to claim 1, whereinthe flexibly elastic characteristics of the tongue-shaped side wallsection (235) exist through the material characteristics of the designcover (280).
 12. The air passage device according to claim 1, wherein inthe upper regions or in the side walls (230 a, 221 a) of the designcover (280) and/or of the base housing (221), at least one tongue-shapedside wall section (235) and at least one holding element (297)corresponding to the tongue-shaped side wall section (235) are providedin the respective corresponding side walls (230 a, 221 a) of the frames(230, 321) of the design cover (280) and/or of the base housing (221).13. The air passage device according to claim 1, wherein thetongue-shaped side wall section (235) with its engagement element (296),and the holding element (297) corresponding therewith, are arrangedcentrally on the side walls (230 a, 221 a) of the frames (230, 321) ofthe design cover (280) and of the base housing (221).
 14. The airpassage device according to claim 1, wherein in the upper regions or inthe side walls (230 a, 221 a) of the design cover (280) corresponding toeach other, and of the base housing (221), two tongue-shaped side wallsections (235) and two holding elements (297) corresponding to thetongue-shaped side wall sections (235) are provided.
 15. The air passagedevice according to claim 1, wherein each tongue-shaped side wallsection (235) has at its free end a section (245′) bent at right-angles,which engages in or behind a correspondingly constructed slight-shapedrecess or opening (239′) in the side wall (221 a) of the frame (321) ofthe base housing (221) corresponding to the side wall (230 a) of thedesign cover (280), as holding element (297).
 16. The air passage deviceaccording to claim 1, wherein each tongue-shaped side wall section (235)of the design cover (280) has a detent cam (245) in the region of itsfree end, wherein on the underside of the side wall (221 a) of the basehousing (221), overlapping the side wall (230 a) of the design cover(280), a correspondingly shaped depression (239) or opening, bore orblind-end bore is provided, corresponding to the shape of the detent cam(245).
 17. The air passage device according to claim 1, wherein thedesign cover (280) and the base housing (221) consist of plastic or of ametal, particularly with flexibly elastic characteristics.
 18. The airpassage device according to claim 1, wherein in the side wall (221 a) ofthe frame (321) of the base housing (221) in the region of thetongue-shaped side wall section (235) in the side wall (230 a) of thedesign cover (280) corresponding to the side wall (221 a) of the basehousing (221), a through-bore or opening (330) is provided.
 19. The airpassage device according to claim 1, wherein the design cover (280) isswivellably arranged on any desired side wall (221 a, 221 b, 221 c, 221d) of the frame (321) of the base housing (221), wherein the detent cams(240) for the design cover (280) and the base housing (221) are providedon the side walls of the design cover (280) lying opposite the swivelaxis for the design cover (280), and the base housing (221).
 20. The airpassage device according to claim 1, wherein to produce the detachabledetent connection (240) between the design cover (280) and the basehousing (221), in at least one of the side walls (221 a, 221 b, 221 c,221 d) of the frame (321) of the base housing (221) at least oneflexible tongue-shaped side wall section (235) is formed from thematerial of the side wall, separated from the remaining side wallsurface by slits (232, 233) running transversely to the longitudinaldirection of the side wall, wherein the tongue-shaped side wall section(235) is held in the side wall (221 a) by means of a cross-piece (238)and on the inner wall side has a holding element (297) in the form of apreferably circular depression (239) or opening, bore or blind-end bore,which is able to be brought into operative connection with an engagementelement (296) in the form of a detent cam (245), which is arranged orformed on the side wall (230 a) of the design cover (280) correspondingto the side wall (221 a) of the base housing (221) having the holdingelement (297), wherein the detent cam (245) is preferably provided atits free end with a section (245 a), partially formed or running in anencircling manner conically to the detent cam end (245 b), as a slidingsurface.
 21. The air passage device according to claim 20, wherein in adetent connection (240) with respectively a holding element (297) and anengagement element (296), these are arranged centrally in the side walls(221 a, 230 a) of the base housing (221) and of the design cover (280).